1. Field of the Invention
The present invention relates to a pitch changing apparatus which changes the pitch of electronic devices when the DUTs are transferred between trays in an electronic device testing apparatus which tests various electronic devices such as semiconductor integrated circuit elements (hereinafter, also referred to as DUTs (Devices Under Test)), an electronic device handling apparatus and the electronic device testing apparatus which include the pitch changing apparatus.
The present application claims priority from Japanese Patent Application No. 2011-289399 filed on Dec. 28, 2011. The contents described and/or illustrated in the documents relevant to the Japanese Patent Application No. 2011-289399 will be incorporated herein by reference as a part of the description and/or drawings of the present application.
2. Description of the Related Art
An apparatus, which transfers DUTs between a customer tray and a test tray before and after a test, is known as an electronic device testing apparatus which tests electronic devices (for example, see International Publication No. WO 2008/041334).
Since DUTs are transferred between trays by a so-called pick-and-place unit in the electronic device testing apparatus, the transfer capacity of the electronic device testing apparatus is limited. Further, a method of improving a capacity of transferring DUTs between trays by making a plurality of shuttles, which have held DUTs, continuously revolve on an endless track is conceivable.
Since the pitch of DUTs needs to be changed so as to correspond to the pitch of destination trays when the DUTs are transferred between trays, the pitch of DUTs also needs to be changed in the case of the above-mentioned shuttle revolving system.